feat/#375: Quasar Upgrade

Feature

Summary

This MR provides…

• Quasar ^1.15.1 -> ^2.6.0

• Vue -> ^3.0.0

• VueX -> ^4.0.1

• Code Refactors.

Note:

Noticed 2 bugs with the upgrade:

• Tree click event of the title doesn't collapse/open the tree structure, works only when click on the arrow. (WIP)
• Scroll behaviour in Text and Annotation panel.

Closes

#375 (closed)